Means for damping motion



1929- E. w. KELLOGG 1,723,864

MEANSFOR D'AMPING MOTION Filed March 25, 1927 I Inve ntor-z Edwahd\XAKeIIcgg y Mw l-1Ls Atto r-ney.

Patented Aug. 6, 1929.

EDWARD 'w. KELLOGG, o1"v scHEuEo'rnDY, nnw YORK, S mon.

TRIO COMPANY, A conronarrou' or-unw Yonk.

' MEANS-FOR miilirm'emo'moni Application ifllledlldiarch 25, -19,27.Serial N'o. 178,477.

My invention relatesto i-neans for damping the motion of vibratingbodies, such as the vibrating parts of anacoustic appara tus or' thecutting tool of an apparatus for 5 making phonograph records,-and hasfor its principal object-the provision of an .improved apparatus andmethod of operation whereby a vibrating body may be subjected I to adamping force which is readily-adjusted in-magnitude, and which, foragiven adjustment,--is--at each instant in such a direction as to opposethe motion of the body and is .proportionalio the'velocity of this-mo-.Vtion.

It has been customary-heretofore to dampen the motion of vibratingbodies by means of devices comprising resilient stops, dash .2 volve theuse, of moving parts or elastic members and, therefore, in addition to"damping, introduce inertia and elasticity efi feats, and theydo notproduce a damping force which is readily adjusted in magni-v tude. Inaccordance with my invention, these difficulties are minimized oraltogether avoided by the provision of an apparatus wherein the currentof a damping element is controlled by means of a space'discharge devicearranged to have-its conductivity varied in proportion to the motion tobe damped.

My invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawings and itsscope will be pointed out in the appended claims.

Referring to the drawings, the figure illustrates a dampingapparatuswherein my invention has been embodied.

up coils I wound ona core 2 and a pair of: coils 11 wound on a core 12.The coils 1 are so arranged that they act on the vibrating member 5which is made of magnetic mato cooperate with the coils. The cores 2 and12 are preferably of a type which carry some permanent magnetic flux.The coils 1 are connected in-the input circuit of a space 5 dischargedevice 6. The output circuit of the space discharge device 6 includes amediate the resistor 17 and the coils-11 and pots, or the like, Many ofthese devices are e not altogethersatisfactory because-they in [core 12.I

This apparatus includes a pair of pickterial or carries a small armaturearranged tential may applied through, former 10. :The secondary 16 ofthe transformer-l5 is 'connefi Ed'to opposed tel:

minals of a 'bridge which includes the coils 1, the ,LCOllS- 11, aresistor lrLand Ti resistor 18, the goods 1 being one arm of the bridge,the.

.coils 2 being another arm ofthe bridge and I the resistors 17 and 18being the other two arms of the bridge. The input circuit "of." thespace discharge device 6 i's'cqnnectedbe-j 5 tween 2. terminalintermediatethe coils 1 and 11 and a terminal intermediate the re-:SISCOI'S l7 and 18, while the secondary winding 16 isconnected'betwee'n a terminal'intera terminal intermediate the coils f1-and a-- resistor 18. A stationary armature 13- is arrangedto-cooperatewith the coilsfl-lan d the 'The'coils 11 and a; core 12areidentica1 '1 with the coils lrand core 2 except that no a motionbetween the; coils I1 "and their armature=13 ispermittedp It should benoted that the output circuitsof the devices 6 and 9 are connected tothe primary circuit 14 of .30 a transformer 15 and that theseconda'ry 16of this transformer is connected to one pair of terminals of the bridgecomprising coils 1 and 11 and resistors 17 and 18 while the otherterminals of this bridgeare connected to the input terminals of thedevice 6.

With these connections, the seconda Lvoltage of the transformer 15 isbalanced with respect to the input circuit of the device 6' but anyvoltage induced in the '-'coils- 1 by motion of the member 5 isisup liedto the input circuit of the device 6 an a current tending. to retard themotion of this member is transmitted through the coils 1.

It owill be apparent that the transformer 15 must supply to the bridgecom rising the coils 1- a secondary current whic is practically in phasewith and proportional to the alternating component of the output circuitof the device 6 throughoutthe essential frequency range. The frequencyat which the member 5 vibrates is of course dependent on the electricalimpulses applied to the primary circuit of the transformer 10.

-The embodiment of the invention illustrated and described herein hasbeen selected for the purpose of clearly setting forth the principlesinvolved. It will be apparent, however, that the invention issusceptible of being modified to meet the difierent condi- 11-0/ tionsencounteredQin its use and il therefore aim to cover by theappended-claims al1- modifications within a the truespirit and scope ofmy invention.

What'I claimasnewlanddesire tosecure 4 .byLettersPatent-o'f the. Unitedstat i d g, dampingfiappamtus icomprismg im spaceidischarge deviceprovided ith; m I

1. The com binatioii of aimo vable body, and? a 'damplng apparatuscomprising-fa space'discharge device provided with input ando'ut'putterminals, a'coil connectedto said input terminals for'applyingthereto a terminals for'siipp'l'ying to said coil currents otentialdependent onmovement 1 of said \and neans connected with said coil toform; o a 'bridge. in' which "the 'output voltage .of

whereby inoti'on' of said bodymay-bepm duced and whereby,- in addition,a damping force 'contrp11ed by,-sai'd potential may be applied'to'saidmember. 4

.2. .The c'oznbination of a movable body,

and a damping apparatus Comprising. a,

space discharge devlceprovidedziwith' input {and output terminals;a'gcoil; connected to p said input terminals for applying theretopbody,a second space discharge device; and

a potential dependent on movement of said body, and means arranged inshunt with-said.

input circuit to lform abridgin which the output of saidl fspacedischarge deviee"Iis-"ba 1 anced with res ect ltd-the "input'circuit;The com b1 iia tion: bf a'mova-ble', and "adampmg *apparatusco'mptking.a;

-' space discharge devlceprovidedwith input and output terminals, a .c'oi1' connected to said input terminals for applying'thereto ,a potentialdependent on movement of and output terminals,- a coil connected. to

-sai d body,-'a second space discharge device,

respect to the input cincuit of said first-met 'tione'd device.

"-1-" 5. The combinationiof a movablebody,

[and a;damping.apparatus--- comprising a andputput terminals, a vcoilconnected to means including a transformer provided to the input circuitof first mentioned said. body,- and' means 1 for applying to said coil aforce whereby'the motion-oi said-r'ndvj. ablesbody is, resisted bythemagnetic 'force o; said.c'0il;' 1,. I i 4. The combination of a movablebody,

space discharge device provided withinput said'= input terminals forapplying thereto a potential dependent on the inovement'of said with aprimary circuit connected to the-out-. a put circuits of said devicesand-with 'a-se'c ondary circuit connected with sa'idcoil to complete abridge wherein the outputvol'tf age of said devices is balanced with'respect' .-..'.65 Y In witness whereof, I have'h'ereunto set'

